1. Field of the Invention
This invention relates generally to rotary cutting tools, and particularly to a tool provided with interchangeable elements permitting the tool to be employed either as a deburring tool or as a flycutter, as desired.
2. Description of the Prior Art
U.S. Pat. No. 2,677,887, issued May 11, 1954, to J. S. Saboda, discloses a circular cutter which includes a separate pair of threaded rods on which tool bit holders are mounted so as to permit a pair of concentric circles to be simultaneously cut in a piece of material. Further, U.S. Pat. No. 2,906,145, issued Sept. 29, 1959, to C. L. Morse, and U.S. Pat. No. 733,821, issued July 14, 1903, to J. G. Dixon, disclose circular cutters and U.S. Pat. No. 1,128,155, issued Feb. 9, 1915, to M. R. Lackey, discloses a bearing scraper which employs only a single rod for mounting a tool holder or holders on a tool assembly. None of these known circular cutting devices has the flexibility, however, to permit either independent or dependent movement of the tool holders to be possible, as desired, to perform a particular cutting function.
For example, when deburring a bushing, and the like, as well as when cutting concentric holes in a workpiece, it is necessary to have independent movement of the tool bit holders. When performing flycutting operations, on the other hand, it is necessary to have dependent movement of the tool bit holders. Although only a single tool bit need be used with a flycutter, as shown in U.S. Pat. No. 3,130,610, issued Apr. 28, 1964, to A. A. Bogdan, it is desirable to employ a pair of bits on the tool bit holder supporting bar of the cutter in order to achieve more rapid and uniform cutting of the workpiece.
U.S. Pat. No. 2,358,741, issued Sept. 19, 1944, to P. Shelby, discloses a countersinking attachment, particularly for use with milling machines which also employs only a single cutting bit holder for the purpose of making flat the bottom of a countersink.